Check the wires and plug attached to the electronic throttle body. If moving the wiring changes the engine RPM or allows the throttle to work you have found your problem. Another problem area is broken wires where the harness runs over the transmission under the clamps. Occasionally the connector to the SECM can have a pin back out or maybe corrosion in this area. Make sure your plugs and wiring to the distributor are ok, can also cause loss of throttle.